Season 12 of NCIS picks up again on Tuesday, Feb. 3 with a new episode.

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Episode 13, which is called We Build, We Fight, is about Gibbs (Mark Harmon) and the team investigating the murder of a Navy lieutenant who was set to be the first openly gay service member to receive the Medal of Honor.

Also, as his wife's due date approaches, Jimmy Palmer (Brian Dietzen) prepares for fatherhood with a NCIS baby shower as stated in the press release for the episode. 

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International Business Times Australian Edition reported Wednesday that despite no mentioning of villain Sergei Mishnev (Alex Veadov), he is expected to return. He killed Diane Sterling (Melinda McGraw) in Episode 11, which was called Check.

Also, in a future episode that is airing on Feb. 17, TVLine reported on Tuesday that it would focus on the aftermath of Diane's death.

The episode is called Cabin Fever and some of it will partake in Gibbs' cabin. Gibbs and Senior FBI Agent Tobias Fornell (Joe Spano) will share many scenes together as they grieve over the loss of Diane.

"There are some really brilliant moments between Mark Harmon and Joe Spano, as they spend some time in Gibbs' cabin and hash out some of the issues they're both facing because of that loss," showrunner Gary Glasberg shared.

Fornell's daughter Emily, who he had with Diane, will also appear in the Feb. 17 episode.

"And Emily makes an appearance too - it's all part of what Fornell is carrying right now. He's having trouble, and Gibbs is there as a friend," Glasberg said.

NCIS airs at 8 p.m. ET on Tuesdays on CBS.

Tags: NCIS television CBS